In many fields, it is desired to guarantee that a product, for example, an ink cartridge, a battery, an accessory, etc., to be used in a device, is an original or authentic product, that is, a product approved by the device manufacturer. To achieve this, an authentication key is generally stored in an electronic circuit associated with this product and is used, when the product is installed in the device or when it should cooperate therewith, to verify that the product is authentic.
However, if the secret can be discovered and a manufacturer commercializes products which are not approved by the device manufacturer, but are however equipped with circuits having the right key, the devices will consider these products as authentic.